The family you never knew you had turns out to be the family you may wish you never met in this arresting, skillfully directed seriocomedy.

– Dennis Harvey

The family you never knew you had turns out to be the family you may wish you never met in Justin Lerner’s “The Automatic Hate.” This arresting seriocomedy deftly walks a tightrope between droll and tense, over a gaping pit of crazy. It will require very careful handling to access appreciative audiences, not least because broadcasting some of its more marketable aspects would amount to major plot spoilage. Film Movement currently plans a limited theatrical release early next year.

Domestic life is already bumpy enough for mild-mannered Bostonian Davis (Joseph Cross): We meet him just as he’s returning from the bathroom to find himself locked out of his own bedroom because (for reasons that are only made clear much later) his professional-dancer girlfriend, Cassie (Deborah Ann Woll), abruptly needs some “alone time.” He’s a successful chef, yet his emotionally distant parents, both academics (Richard Schiff and Caitlin O’Connell), treat that choice of profession as a baffling personal error. He’s further unmoored when a strange young woman, Alexis (Adelaide Clemens), who appears to be stalking him, introduces herself as his cousin — only Davis never knew he had any cousins, or even that his father had a brother.

An investigation of his parents’ basement and brief questioning of his senile grandfather (George Riddle) turns up evidence supporting Alexis’ claim, though it’s apparent that some bad blood between the branches of the family has kept them isolated from one another for decades. Nevertheless, Davis tracks his newfound relative to an upstate New York hamlet where she still lives on the family farm with two sisters (Yvonne and Vanessa Zima) and their parents Ricky Jay and Catherine Carlen). This clan’s slightly chaotic, hippie-ish lifestyle could hardly be more different from his own yuppiefied existence, or his parents’ stiff-necked respectability. An only child, Davis is thrilled to suddenly have three very fun “sisters.” They enjoy his company, too — perhaps a little too much, where the impulsive and needy Alexis is concerned.

But the ruse that he’s simply a new friend to the siblings doesn’t fool Jay’s Uncle Josh, who recognizes him as the child of the brother he refuses to discuss. A chance discovery in the attic of a disused shed teasingly suggests one possible explanation for that long, bitter estrangement. But then a death in the family forces a reunion at which all long-simmering secrets and hostilities finally come tumbling out. This third act hangs largely on a virtuoso dinner set piece whose partial scoring to a Jacques Brel song is, like much of “The Automatic Hate” (including that title), at once mysterious, loopy and just right.

The beguilingly off-kilter film manages to be unsettling in an initially comic mode of dysfunction that grows darker by small degrees, with issues of possible mental illness and worse rumbling beneath the surface. Just when the pic seems to have reached a logical endpoint, a series of savvy epilogues take it further, while underlining perhaps the most definitive statement by a character here: Uncle Josh’s grim acknowledgment that “What we have between us is unresolvable.” Though some viewers may find the sum results unsatisfying and/or unpleasant, it’s a rare film that’s able to maintain such a tricky seriocomic tone throughout.